KRT19 and breast cancer: In the present study, in the group of early breast cancer patients, CTC were isolated according to the AdnaTest BreastCancerTM system from 2 × 5 mL peripheral blood and detected in 36/254 patients by CK-19 RT-qPCR (14.2%), while in the group of 51 patients with overt metastasis, CTC were detected in 21 patients (41.2%) (Table 2).